Motors C API

Note

Additional example code for this module can be found in its Tutorial.

Movement Functions

motor_move

Sets the voltage for the motor from -127 to 127.

This is designed to map easily to the input from the controller’s analog stick for simple opcontrol use. The actual behavior of the motor is analogous to use of motor_move_voltage, or motorSet from the PROS 2 API.

Note

This function will not respect brake modes, and simply sets the voltage to the desired value.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::move.

Prototype
Example
int32_t motor_move ( uint8_t port,
                     const int8_t voltage )

1
2
3
4
5
6
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21
voltage The new motor voltage from -127 to 127

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_move_absolute

Sets the target absolute position for the motor to move to.

This movement is relative to the position of the motor when initialized or the position when it was most recently reset with motor_tare_position.

Note

This function simply sets the target for the motor, it does not block program execution until the movement finishes. The example code shows how to block until a movement is finished.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::move_absolute.

Prototype
Example
int32_t motor_move_absolute ( uint8_t port,
                              double position,
                              int32_t velocity )

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
void autonomous() {
  motor_move_absolute(1, 100, 100); // Moves 100 units forward
  while (!((motor_get_position(1) < 105) && (motor_get_position(1) > 95))) {
    // Continue running this loop as long as the motor is not within +-5 units of its goal
    delay(2);
  }
  motor_move_absolute(1, 100, 100); // This will not cause a movement
  while (!((motor_get_position(1) < 105) && (motor_get_position(1) > 95))) {
    delay(2);
  }

  motor_tare_position(1);
  motor_move_absolute(1, 100, 100); // Moves 100 units forward
  while (!((motor_get_position(1) < 105) && (motor_get_position(1) > 95))) {
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21
position The absolute position to move to in the motor’s encoder units
velocity The maximum allowable velocity for the movement in RPM

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_move_relative

Sets the relative target position for the motor to move to.

This movement is relative to the current position of the motor as given in motor_get_position. Providing 10.0 as the position parameter would result in the motor moving clockwise 10 units, no matter what the current position is.

Note

This function simply sets the target for the motor, it does not block program execution until the movement finishes. The example code shows how to block until a movement is finished.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::move_relative.

Prototype
Example
int32_t motor_move_relative ( uint8_t port,
                              double position,
                              int32_t velocity )

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
void autonomous() {
  motor_move_relative(1, 100, 100); // Moves 100 units forward
  while (!((motor_get_position(1) < 105) && (motor_get_position(1) > 95))) {
    // Continue running this loop as long as the motor is not within +-5 units of its goal
    delay(2);
  }

  motor_move_relative(1, 100, 100); // Also moves 100 units forward
  while (!((motor_get_position(1) < 205) && (motor_get_position(1) > 195))) {
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21
position The relative position to move to in the motor’s encoder units
velocity The maximum allowable velocity for the movement

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_move_velocity

Sets the velocity for the motor.

This velocity corresponds to different actual speeds depending on the gearset used for the motor. This results in a range of +-100 for E_MOTOR_GEARSET_36, +-200 for E_MOTOR_GEARSET_18, and +-600 for blue. The velocity is held with PID to ensure consistent speed, as opposed to setting the motor’s voltage.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::move_velocity.

Prototype
Example
int32_t motor_move_velocity ( uint8_t port,
                              int16_t velocity )

1
2
3
4
5
void autonomous() {
  motor_move_velocity(1, 100);
  delay(1000); // Move at 100 RPM for 1 second
  motor_move_velocity(1, 0);
}
Parameters  
port The V5 port number from 1-21
velocity The new motor velocity from +-100, +-200, or +-600 depending on the motor’s gearset

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_move_voltage

Sets the voltage for the motor from -12000 mV to 12000 mV.

Note

This function will not respect brake modes, and simply sets the voltage to the desired value.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::move_voltage.

Prototype
Example
int32_t motor_move_voltage ( uint8_t port,
                             int16_t voltage )

1
2
3
4
5
void autonomous() {
  motor_move_voltage(1, 12000);
  delay(1000); // Move at max voltage for 1 second
  motor_move_voltage(1, 0);
}
Parameters  
port The V5 port number from 1-21
voltage The new voltage for the motor from -12000 mV to 12000 mV

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_brake

Stops the motor using the currently configured brake mode.

This function sets motor velocity to zero, which will cause it to act according to the set brake mode. If brake mode is set to MOTOR_BRAKE_HOLD, this function may behave differently than calling motor_move_absolute(0) or motor_move_relative(0).

This function uses the following values of errno when an error state is reached:

  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::brake.

Prototype
Example
int32_t motor_brake ( uint8_t port )

1
2
3
4
5
void autonomous() {
  motor_move_voltage(1, 12000);
  delay(1000); // Move at max voltage for 1 second
  motor_brake(1); // Brakes motor
}
Parameters  
port The V5 port number from 1-21

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_modify_profiled_velocity

Changes the output velocity for a profiled movement (motor_move_absolute or motor_move_relative). This will have no effect if the motor is not following a profiled movement.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::modify_profiled_velocity.

Prototype
Example
int32_t motor_modify_profiled_velocity ( uint8_t port,
                                         const int32_t velocity )

1
2
3
4
5
void autonomous() {
  motor_move_absolute(1, 100, 100);
  delay(100);
  motor_modify_profiled_velocity(1, 0); // Stop the motor early
}
Parameters  
port The V5 port number from 1-21
velocity The new motor velocity from +-100, +-200, or +-600 depending on the motor’s gearset

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_get_target_position

Gets the target position set for the motor by the user.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_target_position.

Prototype
Example
double motor_get_target_position ( uint8_t port )

1
2
3
4
5
void autonomous() {
  motor_move_absolute(1, 100, 100);
  printf("Motor Target: %d\n", motor_get_target_position(1));
  // Prints 100
}
Parameters  
port The V5 port number from 1-21

Returns: The target position in its encoder units or PROS_ERR_F if the operation failed, setting errno.

motor_get_target_velocity

Gets the velocity commanded to the motor by the user.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_target_velocity.

Prototype
Example
int32_t motor_get_target_velocity ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move_velocity(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Commanded Velocity: %d\n", motor_get_target_velocity(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The commanded motor velocity from +-100, +-200, +-600, or PROS_ERR if the operation failed, setting errno.

Telemetry Functions

motor_get_actual_velocity

Gets the actual velocity of the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_actual_velocity.

Prototype
Example
double motor_get_actual_velocity ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Actual velocity: %lf\n", motor_get_actual_velocity(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s actual velocity in RPM or PROS_ERR_F if the operation failed, setting errno.

motor_get_current_draw

Gets the current drawn by the motor in mA.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_current_draw.

Prototype
Example
int32_t motor_get_current_draw ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Current Draw: %d\n", motor_get_current_draw(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s current in mA or PROS_ERR if the operation failed, setting errno.

motor_get_direction

Gets the direction of movement for the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_direction.

Prototype
Example
int32_t motor_get_direction ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Direction: %d\n", motor_get_direction(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: 1 for moving in the positive direction, -1 for moving in the negative direction, and PROS_ERR if the operation failed, setting errno.

motor_get_efficiency

Gets the efficiency of the motor in percent.

An efficiency of 100% means that the motor is moving electrically while drawing no electrical power, and an efficiency of 0% means that the motor is drawing power but not moving.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_efficiency.

Prototype
Example
int32_t motor_get_efficiency ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Efficiency: %d\n", motor_get_efficiency(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s efficiency in percent or PROS_ERR_F if the operation failed, setting errno.

motor_get_faults

Gets the faults experienced by the motor.

Compare this bitfield to the bitmasks in motor_fault_e_t.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_faults.

Prototype
Example
uint32_t motor_get_faults ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Faults: %d\n", motor_get_faults(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: Currently unknown bitfield.

motor_get_flags

Gets the flags set by the motor’s operation.

Compare this bitfield to the bitmasks in motor_flag_e_t.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_flags.

Prototype
Example
uint32_t motor_get_flags ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Flags: %d\n", motor_get_flags(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: A currently unknown bitfield

motor_get_position

Gets the absolute position of the motor in its encoder units.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_position.

Prototype
Example
double motor_get_position ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Position: %lf\n", motor_get_position(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s absolute position in its encoder units or PROS_ERR_F if the operation failed, setting errno.

motor_get_power

Gets the power drawn by the motor in Watts.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_power.

Prototype
Example
double motor_get_power ( uint8_t port )

1
2
3
4
5
6
7
8
void opcontrol() {
  uint32_t now = millis();
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Power: %lf\n", motor_get_power(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s power draw in Watts or PROS_ERR_F if the operation failed, setting errno.

motor_get_raw_position

Gets the raw encoder count of the motor at a given timestamp.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_raw_position.

Prototype
Example
int32_t motor_get_raw_position ( uint8_t port,
                                 uint32_t* timestamp )

1
2
3
4
5
6
7
8
void opcontrol() {
  uint32_t now = millis();
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Encoder Count: %d\n", motor_get_raw_position(1, &now));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21
timestamp A pointer to a time in milliseconds for which the encoder count will be returned

Returns: The raw encoder count at the given timestamp or PROS_ERR if the operation failed, setting errno.

motor_get_temperature

Gets the temperature of the motor in degrees Celsius. The resolution of this eading is 5 degrees Celsius. The motor will start to reduce its power when the temperature reading is greater than or equal to 55 C.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_temperature.

Prototype
Example
double motor_get_temperature ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Temperature: %lf\n", motor_get_temperature(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s temperature in degrees Celsius or PROS_ERR_F if the operation failed, setting errno.

motor_get_torque

Gets the torque generated by the motor in Nm.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_torque.

Prototype
Example
double motor_get_torque ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Torque: %lf\n", motor_get_torque(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s torque in NM or PROS_ERR_F if the operation failed, setting errno.

motor_get_voltage

Gets the voltage delivered to the motor in mV.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_voltage.

Prototype
Example
int32_t motor_get_voltage ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Voltage: %d\n", motor_get_voltage(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s voltage in mV or PROS_ERR_F if the operation failed, setting errno.

motor_get_zero_position_flag

Gets the zero position flag for the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_zero_position_flag.

Prototype
Example
int32_t motor_get_zero_position_flag ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Is the motor at its zero position? %d\n", motor_get_zero_position_flag(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: 1 if the motor is at zero absolute position and 0 if the motor has moved from its absolute zero, or PROS_ERR if the operation failed setting errno.

motor_is_stopped

Gets the zero velocity flag for the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::is_stopped.

Prototype
Example
int32_t motor_is_stopped ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Is the motor stopped? %d\n", motor_is_stopped(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: 1 if the motor is not moving and 0 if the motor is moving, or PROS_ERR if the operation failed, setting errno.

motor_is_over_current

Detects if the motor is drawing over its current limit.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::is_over_current.

Prototype
Example
int32_t motor_is_over_current ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Current Limit Hit?: %d\n", motor_is_over_current(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: 1 if the motor’s current limit is being exceeded and 0 if the current limit is not exceeded, or PROS_ERR if the operation failed, setting errno.

motor_is_over_temp

Gets the temperature limit flag for the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::is_over_temp.

Prototype
Example
int32_t motor_is_over_temp ( uint8_t port )

1
2
3
4
5
6
7
void opcontrol() {
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    printf("Motor Temp Limit: %d\n", motor_is_over_temp(1));
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: 1 if the temperature limit is exceeded and 0 if the the temperature is below the limit, or PROS_ERR if the operation failed, setting errno.

Configuration Functions

motor_get_brake_mode

Gets the brake mode of the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_brake_mode.

Prototype
Example
motor_brake_mode_e_t motor_get_brake_mode ( uint8_t port )

void initialize() {
  motor_set_brake_mode(1, E_MOTOR_BRAKE_HOLD);
  printf("Brake Mode: %d\n", motor_get_brake_mode(1));
}
Parameters  
port The V5 port number from 1-21

Returns: One of motor_brake_mode_e_t, according to what was set for the motor, or E_MOTOR_BRAKE_INVALID if the operation failed, setting errno.

motor_get_current_limit

Gets the current limit for the motor in mA. The default limit is 2500 mA.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_current_limit.

Prototype
Example
int32_t motor_get_current_limit ( uint8_t port )

void initialize() {
  printf("Motor Current Limit: %d\n", motor_get_current_limit(1));
  // Prints "Motor Current Limit: 2500"
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s current limit in mA or PROS_ERR if the operation failed, setting errno.

motor_get_encoder_units

Gets the encoder units set for the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_encoder_units.

Prototype
Example
motor_encoder_units_e_t motor_get_encoder_units ( uint8_t port )

void initialize() {
  printf("Motor Encoder Units: %d\n", motor_get_encoder_units(1));
  // Prints E_MOTOR_ENCODER_DEGREES by default
}
Parameters  
port The V5 port number from 1-21

Returns: One of motor_encoder_units_e_t according to what is set for the motor or E_MOTOR_ENCODER_INVALID if the operation failed.

motor_get_gearing

Gets the gearset <motors.html#motor-gearset-e-t>`_ that was set for the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_gearing.

Prototype
Example
motor_gearset_e_t motor_get_gearing ( uint8_t port )

void initialize() {
  printf("Motor Gearing Number: %d\n", motor_get_gearing(1));
  // Prints E_MOTOR_GEARSET_36 by default
}
Parameters  
port The V5 port number from 1-21

Returns: One of motor_gearset_e_t according to what is set for the motor, or E_GEARSET_INVALID if the operation failed.

motor_get_voltage_limit

Gets the voltage limit set by the user.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::get_voltage_limit.

Prototype
Example
int32_t motor_get_voltage_limit ( uint8_t port )

void initialize() {
  printf("Motor Voltage Limit: %d\n", motor_get_voltage_limit(1));
  // Prints 0 by default, indicating no limit
}
Parameters  
port The V5 port number from 1-21

Returns: The motor’s voltage limit in V or PROS_ERR if the operation failed, setting errno.

motor_is_reversed

Gets the operation direction of the motor as set by the user.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::is_reversed.

Prototype
Example
int32_t motor_is_reversed ( uint8_t port )

void initialize() {
  printf("Is the motor reversed? %d\n", motor_is_reversed(1));
  // Prints "Is the motor reversed? 0"
}
Parameters  
port The V5 port number from 1-21

Returns: 1 if the motor has been reversed and 0 if the motor was not reversed, or PROS_ERR if the operation failed, setting errno.

motor_set_brake_mode

Sets one of motor_brake_mode_e_t to the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::set_brake_mode.

Prototype
Example
int32_t motor_set_brake_mode ( uint8_t port,
                               motor_brake_mode_e_t mode )

void initialize() {
  motor_set_brake_mode(1, E_MOTOR_BRAKE_HOLD);
  printf("Brake Mode: %d\n", motor_get_brake_mode(1));
}
Parameters  
port The V5 port number from 1-21
mode The motor_brake_mode_e_t to set for the motor

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_set_current_limit

Sets the current limit for the motor in mA.

The default limit is 2500 mA.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::set_current_limit.

Prototype
Example
int32_t motor_set_current_limit ( uint8_t port,
                                  int32_t limit )

1
2
3
4
5
6
7
8
void opcontrol() {
  motor_set_current_limit(1, 1000);
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    // The motor will reduce its output at 1000 mA instead of the default 2500 mA
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21
limit The new current limit in mA

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_set_encoder_units

Sets one of motor_encoder_units_e_t for the motor encoder.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::set_encoder_units.

Prototype
Example
int32_t motor_set_encoder_units ( uint8_t port,
                                  motor_encoder_units_e_t units )

void initialize() {
  motor_set_encoder_units(1, E_MOTOR_ENCODER_DEGREES);
  printf("Encoder Units: %d\n", motor_get_encoder_units(1));
}
Parameters  
port The V5 port number from 1-21
units The new motor encoder units

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_set_gearing

Sets one of motor_gearset_e_t for the motor.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::set_gearing.

Prototype
Example
int32_t motor_set_gearing ( uint8_t port,
                            motor_gearset_e_t gearset )

void initialize() {
  motor_set_gearing(1, E_MOTOR_GEARSET_06);
  printf("Brake Mode: %d\n", motor_get_gearing(1));
}
Parameters  
port The V5 port number from 1-21
gearset The new motor gearset

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_set_reversed

Sets the reverse flag for the motor.

This will invert its movements and the values returned for its position.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::set_reversed.

Prototype
Example
int32_t motor_set_reversed ( uint8_t port,
                             bool reverse )

void autonomous() {
  motor_set_reversed(1, true);
  printf("Is this motor reversed? %d\n", motor_is_reversed(1));
}
Parameters  
port The V5 port number from 1-21
reverse 1 reverses the motor, 0 is default

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_set_voltage_limit

Sets the voltage limit for the motor in mV.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::set_voltage_limit.

Prototype
Example
int32_t motor_set_voltage_limit ( uint8_t port,
                                  int32_t limit )

1
2
3
4
5
6
7
8
void autonomous() {
  motor_set_voltage_limit(1, 10000);
  while (true) {
    motor_move(1, controller_get_analog(E_CONTROLLER_MASTER, E_CONTROLLER_ANALOG_LEFT_Y));
    // The motor will not output more than 10 V
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21
limit The new voltage limit in mV

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_set_zero_position

Sets the zero position for the motor in its encoder units.

This will be the future reference point for the motor’s “absolute” position.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::set_zero_position.

Prototype
Example
int32_t motor_set_zero_position ( uint8_t port,
                                  double position )

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
void autonomous() {
  motor_move_absolute(1, 100, 100); // Moves 100 units forward
  while (!((motor_get_position(1) - 100 < 105) && (motor_get_position(1) - 100 > 95))) {
    // Continue running this loop as long as the motor is not within +-5 units of its goal
    delay(2);
  }
  motor_move_absolute(1, 100, 100); // This does not cause a movement
  while (!((motor_get_position(1) - 100 < 105) && (motor_get_position(1) - 100 > 95))) {
    delay(2);
  }

  motor_set_zero_position(1, 80);
  motor_move_absolute(1, 100, 100); // Moves 80 units forward
  while (!((motor_get_position(1) - 100 < 105) && (motor_get_position(1) - 100 > 95))) {
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21
position The new reference position in its encoder units

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

motor_tare_position

Sets the “absolute” zero position of the motor to its current position.

This function uses the following values of errno when an error state is reached:

  • ENXIO - The given value is not within the range of V5 ports (1-21).
  • ENODEV - The port cannot be configured as a motor

Analogous to pros::Motor::tare_position.

Prototype
Example
int32_t motor_tare_position ( uint8_t port )

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
void autonomous() {
  motor_move_absolute(1, 100, 100); // Moves 100 units forward
  while (!((motor_get_position(1) - 100 < 105) && (motor_get_position(1) - 100 > 95))) {
    // Continue running this loop as long as the motor is not within +-5 units of its goal
    delay(2);
  }
  motor_move_absolute(1, 100, 100); // This does not cause a movement
  while (!((motor_get_position(1) - 100 < 105) && (motor_get_position(1) - 100 > 95))) {
    delay(2);
  }

  motor_tare_position(1);
  motor_move_absolute(1, 100, 100); // Moves 100 units forward
  while (!((motor_get_position(1) - 100 < 105) && (motor_get_position(1) - 100 > 95))) {
    delay(2);
  }
}
Parameters  
port The V5 port number from 1-21

Returns: 1 if the operation was successful or PROS_ERR if the operation failed, setting errno.

Macros

None.

Enumerated Values

motor_brake_mode_e_t

Indicates the current ‘brake mode’ of the motor.

1
2
3
4
5
6
typedef enum motor_brake_mode_e {
  E_MOTOR_BRAKE_COAST = 0, // Motor coasts when stopped, traditional behavior
  E_MOTOR_BRAKE_BRAKE = 1, // Motor brakes when stopped
  E_MOTOR_BRAKE_HOLD = 2, // Motor actively holds position when stopped
  E_MOTOR_BRAKE_INVALID = INT32_MAX
} motor_brake_mode_e_t;
Value  
E_MOTOR_BRAKE_COAST Motor coasts when stopped, traditional behavior
E_MOTOR_BRAKE_BRAKE Motor brakes when stopped
E_MOTOR_BRAKE_HOLD Motor actively holds position when stopped
E_MOTOR_BRAKE_INVALID Invalid brake mode

motor_encoder_units_e_t

Indicates the units used by the motor’s encoder.

1
2
3
4
5
6
7
8
9
typedef enum motor_encoder_units_e {
  E_MOTOR_ENCODER_DEGREES = 0,   // Position is recorded as angle in degrees
                                 // as a floating point number
  E_MOTOR_ENCODER_ROTATIONS = 1, // Position is recorded as angle in rotations
                                 // as a floating point number
  E_MOTOR_ENCODER_COUNTS = 2,    // Position is recorded as raw encoder ticks
                                 // as a whole number
  E_MOTOR_ENCODER_INVALID = INT32_MAX
} motor_encoder_units_e_t;
Value  
E_MOTOR_ENCODER_DEGREES Position is recorded as angle in degrees as a floating point number
E_MOTOR_ENCODER_ROTATIONS Position is recorded as angle in rotations as a floating point number
E_MOTOR_ENCODER_COUNTS Position is recorded as raw encoder ticks as a whole number
E_MOTOR_BRAKE_INVALID Invalid motor encoder units

motor_fault_e_t

1
2
3
4
5
6
7
typedef enum motor_fault_e {
      E_MOTOR_FAULT_NO_FAULTS = 0x00,
      E_MOTOR_FAULT_MOTOR_OVER_TEMP = 0x01,  // Analogous to motor_is_over_temp()
      E_MOTOR_FAULT_DRIVER_FAULT = 0x02,     // Indicates a motor h-bridge fault
      E_MOTOR_FAULT_OVER_CURRENT = 0x04,     // Analogous to motor_is_over_current()
      E_MOTOR_FAULT_DRV_OVER_CURRENT = 0x08  // Indicates an h-bridge over current
} motor_fault_e_t;
Value  
E_MOTOR_FAULT_NO_FAULTS No faults
E_MOTOR_BRAKE_BRAKE Motor brakes when stopped
E_MOTOR_BRAKE_HOLD Motor actively holds position when stopped
E_MOTOR_BRAKE_INVALID Invalid brake mode

motor_flag_e_t

1
2
3
4
5
6
typedef enum motor_flag_e {
  E_MOTOR_FLAGS_NONE = 0x00,
  E_MOTOR_FLAGS_BUSY = 0x01,           // Cannot currently communicate to the motor
  E_MOTOR_FLAGS_ZERO_VELOCITY = 0x02,  // Analogous to motor_is_stopped()
  E_MOTOR_FLAGS_ZERO_POSITION = 0x04   // Analogous to motor_get_zero_position_flag()
} motor_flag_e_t;
Value  
E_MOTOR_FLAGS_NONE There are no flags raised
E_MOTOR_FLAGS_BUSY Cannot currently communicate to the motor
E_MOTOR_FLAGS_ZERO_VELOCITY Analogous to motor_is_stopped()
E_MOTOR_FLAGS_ZERO_POSITION Analogous to motor_get_zero_position_flag()

motor_gearset_e_t

Indicates the internal gearing used by the motor.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
typedef enum motor_gearset_e {
  E_MOTOR_GEARSET_36 = 0, // 36:1
  E_MOTOR_GEAR_RED = E_MOTOR_GEARSET_36, // Red gear set
  E_MOTOR_GEAR_100 = E_MOTOR_GEARSET_36, // 100 RPM
  E_MOTOR_GEARSET_18 = 1, // 18:1
  E_MOTOR_GEAR_GREEN = E_MOTOR_GEARSET_18, // Green gear set
  E_MOTOR_GEAR_200 = E_MOTOR_GEARSET_18, // 200 RPM
  E_MOTOR_GEARSET_06 = 2, // 6:1
  E_MOTOR_GEAR_BLUE  = E_MOTOR_GEARSET_06, // Blue gear set
  E_MOTOR_GEAR_600 = E_MOTOR_GEARSET_06, // 600 RPM
  E_MOTOR_GEARSET_INVALID = INT32_MAX
} motor_gearset_e_t;
Value  
E_MOTOR_GEARSET_36 36:1
E_MOTOR_GEAR_RED Red gear set
E_MOTOR_GEAR_100 100 RPM
E_MOTOR_GEARSET_18 18:1
E_MOTOR_GEAR_GREEN Green gear set
E_MOTOR_GEAR_200 200 RPM
E_MOTOR_GEARSET_06 6:1
E_MOTOR_GEAR_BLUE Blue Gear Set
E_MOTOR_GEAR_600 200 RPM
E_MOTOR_GEARSET_INVALID Error return code